Ultra-wideband localization has become a key solution for a variety of industrial applications and recently challenged a significant amount of research. Most of the current research however, focusses primarily on the analysis of the localization accuracy of one or few mobile users in well-defined system environments. This work aims to analyze the interdependency of various system performance criteria, in particular multi-user scalability, real-time capability and energy efficiency of time of arrival based wireless localization. We provide an overview by comparing the predominant system topologies and develop analytical models validated by experiments to evaluate the individual trade-offs. Furthermore, we provide an implementation proposal and in-depth evaluation of emerging time-difference of arrival scheduled channel access to allow for reliable, highly scalable and energy efficient localization enabling a paradigm shift for many industrial applications. We could show that compared to the most commonly used schemes, the number of users and the energy consumption can be improved by orders of magnitude.